Response of soil respiration to a severe drought in Chinese Eucalyptus plantations

作     者：Shaojun Wang Hong Wang 

作者机构：Department of Environmental Science and EngineeringSouthwest Forestry University Co-Innovation Center for Sustainable Forestry in Southern China College of Biology and the Environment Nanjing Forestry University 

出 版 物：《Journal of Forestry Research》 (林业研究（英文版）)

年 卷 期：2017年第28卷第4期

页      面：841-847页

核心收录：

学科分类：090703[农学-森林保护学] 0907[农学-林学] 09[农学] 0903[农学-农业资源与环境] 090301[农学-土壤学] 

基　　金：supported by National Natural Science Foundation of China(41461052) China 948 Program of State Forestry Administration(2015-4-39) Fund Project to Start Science Research in Southwest Forestry University(111206) 

主　　题：Drought Eucalyptus globulus Global change Soil respiration 

摘      要：Extreme droughts can adversely affect the dynamics of soil respiration in tree plantations. We used a severe drought in southwestern China as a case study to estimate the effects of drought on temporal variations in soil respiration in a plantation of Eucalyptus globulus. We documented a clear seasonal pattern in soil respiration with the highest values (100.9 mg C-CO2 m(-2) h(-1)) recorded in June and the lowest values (28.7 mg C-CO2 m(-2) h(-1)) in January. The variation in soil respiration was closely associated with the dynamics of soil water driven by the drought. Soil respiration was nearly twice as great in the wet seasons as in the dry seasons. Soil water content accounted for 83-91% of variation in soil respiration, while a combined soil water and soil temperature model explained 90-99% of the variation in soil respiration. Soil water had pronounced effects on soil respiration at the moisture threshold of 6-10%. Soil water was strongly related to changes in soil parameters (i.e., bulk density, pH, soil organic carbon, and available nitrogen). These strongly influenced seasonal variation in soil respiration. We found that soil respiration was strongly suppressed by severe drought. Drought resulted in a shortage of soil water which reduced formation of soil organic carbon, impacted soil acid-base properties and soil texture, and affected soil nutrient availability.